Arylamine compound and organic electroluminescence device containing the same

ABSTRACT

Provided are a novel arylamine compound of a specific structure having at least one spiro bond; an organic EL device in which an organic compound layer comprising one layer or plural layers including at least a luminescent layer is interposed between a cathode and an anode, wherein at least one of the above organic compound layers contains the arylamine derivative described above; an organic EL device in which an organic compound layer comprising one layer or plural layers including at least a luminescent layer is interposed between a cathode and an anode, wherein at least one of the above organic compound layers contains the arylamine derivative described above and a luminescent material; and an organic EL device in which an organic compound layer comprising one layer or plural layers including at least a luminescent layer is interposed between a cathode and an anode, wherein the above organic compound layer is prepared by laminating a hole transporting layer containing the arylamine derivative described above and a luminescent layer comprising a phosphorescence-emitting metal complex and a host material. Provided are an organic EL device which has a high luminance, a high heat resistance and a long life and which is excellent in a hole transporting property and has a high luminous efficiency and a novel arylamine compound which realizes the same.

BACKGROUND OF THE INVENTION

The present invention relates to a novel arylamine compound and anorganic electroluminescent device using the same, specifically to anorganic electroluminescent device which has a high luminance, a highheat resistance and a long life and which is excellent in a holetransporting property and has a high luminous efficiency and a novelarylamine compound which realizes the same.

RELATED ART

An organic electroluminescent (EL) device using an organic substance isused as a light source for a plane emitter for a wall-mounted televisionset and a backlight for a display, and it has actively been developed.An electroluminescent phenomenon of organic materials was observed onanthracene single crystal by Pope et al. in 1963 (J. Chem. Phys. 38(1963) 2042), and Helfinch and Schneider succeeded in observingrelatively strong injection type EL by using a solution electrode systemhaving a good injection efficiency (Phys. Rev. Lett. 14 (1965 229). Asreported since then, it has been researched to form organic luminoussubstances from conjugate organic host substances and conjugate organicactivators having condensed benzene rings. Shown as the examples of theorganic host substances were naphthalene, anthracene, phenanthrene,tetracene, pyrene, benzopyrene, chrysene, picene, carbazole, fluorene,biphenyl, terphenyl, triphenylene oxide, dihalobiphenyl, trans-stilbeneand 1,4-diphenylbutadiene, and anthracene, tetracene and pentacene weregiven as the examples of the activators. However, all of the aboveorganic luminous substances were present in the form of a single layerhaving a thickness exceeding 1 μm, and a high electric field wasrequired for luminescence. Accordingly, research of thin film devices bya vacuum vapor deposition method was promoted (for example, Thin SolidFilms 94 (1982) 171). However, though a reduction in a film thicknesswas effective for a reduction in a driving voltage, it did not come toobtain a device of a practical use level having a high luminance. Then,Tang et al. devised an EL device prepared by laminating two very thinfilms (a hole transporting layer and a luminescent layer) between ananode and a cathode by vacuum vapor deposition to realize a highluminance at a low driving voltage (Appl. Phys. Lett. 51 (1987) 913 orU.S. Pat. No. 4,356,429). Then, developments of organic compounds usedfor a hole transporting layer and a luminescent layer were promoted forten and several years, and as a result thereof, an organic EL device wasstarted being put into practical use in display parts of car stereos andportable telephones.

However, durability of the luminance against deterioration with thepassage of time in use for long time is not satisfactory in terms ofactual use and required to be further improved. In particular, whenconsidering application thereof to full color displays, it is requiredto the respective colors of R, G and B to achieve a half life of severalthousand hours at a high luminance of 300 cd/m² or more. It isparticularly difficult in phosphorescent type luminescence to achievethis. Energy gap in a luminescent layer is as large as 3.0 eV or more,and large energy barrier is present between a hole transporting layerand a luminescent layer in injecting a hole, so that a field intensityapplied to the interface is large, and a hole can not stably be injectedin a conventional hole transporting layer. Accordingly, improvementthereof has been required. Further, on the assumption that an organic ELdevice is mounted on a car, a preserving performance thereof at a hightemperature is required, but it is pointed out that it has a problem ona preserving performance at a high temperature of 100° C. or higher.Also in this case, it is pointed out that a glass transition temperatureis low in a conventional hole transporting layer, and it has been triedto cope therewith only by improving the glass transition temperature to100° C. or higher, but it is unsatisfactory, and the good preservingperformance at a high temperature has not yet been realized.

Various inventions have been made in order to solve the problemsdescribed above, and a luminescent device in which a compoundrepresented by the following Formula (A) is used as a hole transportingmaterial is disclosed in, for example, Japanese Patent ApplicationLaid-Open No. 25473/1993:

wherein R¹¹ represents an alkyl group or an aralkyl group, and R¹² toR¹⁵ represent a hydrogen atom, an alkyl group, an alkoxy group or ahalogen atom.

However, the above compound had a glass transition temperature of 100°C. or lower, and a device prepared by using the same had a short lifeand was short of a heat resistance, so that it could not be put intopractical use. Further, known is a compound obtained by changing R¹² toR¹⁵ to aryl groups in order to improve the above matter, but it isscarcely soluble and therefore hard to be highly purified, so that aproblem has been involved in using it as a material for a long lifedevice.

Further, a luminescent device in which a compound represented by thefollowing Formula (B) is used as a hole transporting material isdisclosed in Japanese Patent Application Laid-Open No. 288783/1999:

wherein Ar₁ to Ar₃ each represent a substituted or non-substituted arylgroup, and Ar₂ and Ar₃ may form a nitrogen-containing heterocycletogether with a nitrogen atom to which they are bonded; R₁ and R₂ eachrepresent a hydrogen atom, a linear, branched or cyclic alkyl group, asubstituted or non-substituted aryl group or a substituted ornon-substituted aralkyl group; Z₁ and Z₂ each represent a hydrogen atom,a halogen atom, a linear, branched or cyclic alkyl group, a linear,branched or cyclic alkoxy group or a substituted or non-substituted arylgroup; and X represents a substituted or non-substituted arylene group.

A fluorene group is introduced into the above compounds, but the glasstransition temperatures are still low and have been required to beimproved. Further, the fluorene groups present at the ends thereof havea high flatness and therefore cause interactions (exiplex,charge-transfer complex and the like) with compounds in the other layersin constituting a laminate, so that there used to be involved thereinthe problem that a luminescent efficiency of the devices is reduced.

DISCLOSURE OF THE INVENTION

The present invention has been made in order to solve the problemsdescribed above, and an object thereof is to provide an organic ELdevice which has a high luminance, a high heat resistance and a longlife and which is excellent in a hole transporting property and has ahigh luminous efficiency and a novel arylamine compound which realizesthe same.

Intensive researches repeated by the present inventors in order toachieve the object described above have resulted in finding that use ofan arylamine compound of a specific structure having at least one spirobond provides an organic EL device which has a high heat resistance anda long life because of a high glass transition temperature and which isexcellent in a hole transporting property and has a high luminousefficiency because of increased steric hindrance and less liability ofassociation due to a flatness of molecules which is reduced bycontaining the specific spiro bond, and thus they have come to completethe present invention.

That is, the present invention provides an arylamine compoundrepresented by the following Formula (1):

wherein X is a substituted or non-substituted aromatic hydrocarbon grouphaving 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; Ar¹, Ar², Ar³ and Ar⁴each are independently a substituted or non-substituted aryl grouphaving 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; provided that at leastone of Ar¹, Ar², Ar³ and Ar⁴ is a group represented by the followingFormula (2); Ar¹, Ar², Ar³ and Ar⁴ may be the same as or different fromeach other, and they may be combined with adjacent ones to form asaturated or unsaturated ring; and p is an integer of 0 to 2:

wherein R¹ and R² each are independently a hydrogen atom, a substitutedor non-substituted amino group, a substituted or non-substituted alkylgroup having 1 to 50 carbon atoms, a substituted or non-substituted arylgroup having 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; R³ represents an atomicgroup which forms a cyclic structure; Ar⁵ is a single bond or a divalentgroup comprising a substituted or non-substituted aromatic hydrocarbongroup having 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; L is a single bond, —O—,—S—, —NR⁴— or —CR⁵R⁶— (R⁴, R⁵ and R⁶ each are independently asubstituted or non-substituted alkyl group having 1 to 50 carbon atomsor a substituted or non-substituted aryl group having 6 to 40 carbonatoms); s, q and r each are an integer of 0 to 2; and R¹ and R² may becombined with each other to form a ring.

Further, the present invention provides an organic EL device in which anorganic compound layer comprising one layer or plural layers includingat least a luminescent layer is interposed between a cathode and ananode, wherein at least one of the above organic compound layerscontains the arylamine derivative described above; an organic EL devicein which an organic compound layer comprising one layer or plural layersincluding at least a luminescent layer is interposed between a cathodeand an anode, wherein at least one of the above organic compound layerscontains the arylamine derivative described above and a luminescentmaterial; and an organic EL device in which an organic compound layercomprising one layer or plural layers including at least a luminescentlayer is interposed between a cathode and an anode, wherein the aboveorganic compound layer is prepared by laminating a hole transportinglayer containing the arylamine derivative described above and aluminescent layer comprising a phosphorescence-emitting metal complexand a host material.

BEST MODE FOR CARRYING OUT THE INVENTION

The arylamine compound of the present invention is represented by thefollowing Formula (1):

In Formula (1), X is a substituted or non-substituted aromatichydrocarbon group having 6 to 40 carbon atoms or a substituted ornon-substituted heterocyclic group having 5 to 40 carbon atoms.

The examples of the aromatic hydrocarbon group represented by X includemonovalent, divalent or trivalent residues of benzene, biphenyl,terphenyl, naphthalene, fluorene, pyrene, spirobifluorene and stilbene,and benzene and condensed aromatic ring residues of naphthalene,fluorene and pyrene are preferred.

The examples of the heterocyclic group represented by X includemonovalent, divalent or trivalent residues of carbazole, dibenzofurane,dibenzothiophene, fluorenone, oxazole, oxadiazole, thiadiazole andbenzimidazole, and the residues of carbazole and benzimidazole arepreferred.

The substituents for the above groups include halogen atoms such as afluorine atom, a chlorine atom, a bromine atom and an iodine atom, alkylgroups such as methyl, ethyl, n-propyl and iso-propyl, alkoxy groupssuch as methoxy, ethoxy and phenoxy, aralkyl groups such as benzyl,phenethyl and propylphenyl, a nitro group, a cyano group, substitutedamino groups such as dimethylamino, dibenzylamino, diphenylamino andmorpholino, aryl groups such as phenyl, toluyl, biphenyl, naphthyl,anthryl and pyrenyl and heterocyclic groups such as pyridyl, thienyl,furyl, quinolyl and carbazolyl.

In Formula (1), Ar¹, Ar², Ar³ and Ar⁴ each are independently asubstituted or non-substituted aryl group having 6 to 40 carbon atoms ora substituted or non-substituted heterocyclic group having 5 to 40carbon atoms.

Provided that at least one of Ar¹, Ar², Ar³ and Ar⁴ is a grouprepresented by the following Formula (2), and two to four of them arepreferably the group represented by the following Formula (2).

Further, Ar¹, Ar², Ar³ and Ar⁴ may be the same as or different from eachother, and they may be combined with adjacent ones to form a saturatedor unsaturated ring.

The examples of the aryl group represented by Ar¹ to Ar⁴ include phenyl,biphenyl, terphenyl, naphthyl, fluorenyl, pyrenyl, spirobifluorenyl andstilbenyl, and phenyl and condensed polycyclic aromatic groups such asnaphthyl, fluorenyl and pyrenyl are preferred.

The examples of the heterocyclic group represented by Ar¹ to Ar⁴ includecarbazolyl, dibenzofuranyl, dibenzothiophenyl, fluorenonyl, oxazolyl,oxadiazolyl, thiadiazole and benzimidazole, and carbazolyl andbenzimidazole are preferred.

The substituents for the above groups include the same ones as explainedin X described above.

In the arylamine compound of the present invention, at least two of Ar¹to Ar⁴ in Formula (1) are preferably aromatic hydrocarbons having 10 ormore carbon atoms, and further preferably, at least two of Ar¹ to Ar⁴are substituted or non-substituted biphenyl or at least one of Ar¹ toAr⁴ is a group substituted with a diarylamino group.

The term p is an integer of 0 to 2.

In Formula (2), R¹ and R² each are independently a hydrogen atom, asubstituted or non-substituted amino group, a substituted ornon-substituted alkyl group having 1 to 50 carbon atoms, a substitutedor non-substituted aryl group having 6 to 40 carbon atoms or asubstituted or non-substituted heterocyclic group having 5 to 40 carbonatoms.

The substituted or non-substituted amino group represented by R¹ and R²includes phenylamino, dimethylamino, benzylamino, diphenylamino andmorpholino.

The alkyl group represented by R¹ and R² includes methyl, ethyl,n-propyl, iso-propyl, n-butyl, s-butyl and t-butyl.

The aryl group and the heterocyclic group represented by R¹ and R²include the same ones as explained in Ar¹ to Ar⁴ described above.

The substituents for the above groups include the same ones as explainedin X described above.

R¹ and R² may be combined with each other to form a ring.

R³ represents an atomic group which forms a cyclic structure andincludes, for example, alkylene groups such as an ethylene group, apropylene group, a n-butylene group, a n-pentylene group and an-hexylene group and groups in which at least one of the above alkylenegroups is substituted with a nitrogen atom or an oxygen atom to form aheterocycle. They may have substituents. Further, the substituents maybe combined with each other to form an unsaturated ring. Thesubstituents include the same ones as explained in X described above.

The specific examples of the group represented by Formula (2) includethe following ones:

In Formula (2), Ar⁵ is a single bond or a divalent group comprising asubstituted or non-substituted aromatic hydrocarbon group having 6 to 40carbon atoms or a substituted or non-substituted heterocyclic grouphaving 5 to 40 carbon atoms.

The examples of the aromatic hydrocarbon group represented by Ar⁵include divalent residues of benzene, biphenyl, terphenyl, naphthalene,fluorene, pyrene spirofluorene and stilbene.

The examples of the heterocyclic group represented by Ar⁵ includedivalent residues of carbazole, dibenzofurane, dibenzothiophene,fluorenone, oxazole, oxadiazole, thiadiazole and benzimidazole.

The substituents for the above groups include the same ones as explainedin X described above.

In Formula (2), L is a single bond, —O—, —S—, —NR⁴— or —CR⁵R⁶— (R⁴, R⁵and R⁶ each are independently a substituted or non-substituted alkylgroup having 1 to 50 carbon atoms or a substituted or non-substitutedaryl group having 6 to 40 carbon atoms).

The specific examples of the alkyl group and the aryl group representedby R⁴, R⁵ and R⁶ and the substituents therefor include the same ones asexplained in R¹ and R² described above.

The terms s, q and r each are an integer of 0 to 2.

The arylamine compound of the present invention represented by Formula(1) is obtained, for example, by reacting a corresponding iodo compoundwith a corresponding amine compound. The reaction is preferably carriedout under the presence of a catalyst, and the catalyst includes a metalcatalyst, for example, a copper catalyst.

The example of a production process for the arylamine compound of thepresent invention includes the following route. That is, an iodocompound represented by the following Formula (3):I—X—I  (3)(wherein X is the same as described above) is reacted with an aminecompound represented by the following Formula (4) or Formula (4) andFormula (5):

(wherein Ar¹ to Ar⁴ are the same as described above) to obtain thearylamine compound represented by Formula (1).

The specific examples of the arylamine compound of the present inventionrepresented by Formula (1) shall be shown below, but they shall not berestricted to these compounds shown as the examples.

The arylamine compound of the present invention is useful as a materialfor an organic EL device, and it is particularly preferably used as ahole transporting material.

The device structure of the organic EL device of the present inventionshall be explained below.

In the organic EL device of the present invention in which an organiccompound layer comprising a single layer or plural layers including atleast a luminescent layer is interposed between a cathode and an anode,at least one layer of the above organic compound layers contains thearylamine compound of the present invention described above.

The organic EL device is improved in a luminance, a heat resistance, alife and a luminous efficiency by adding the arylamine compound of thepresent invention to at least one layer of the organic compound layersbecause the arylamine compound is excellent in a hole transportingproperty, and a hole can stably be injected; a glass transitiontemperature is high; a flatness of molecules is reduced due to a spirobond contained therein, so that steric hindrance is increased; it isless liable to interact with the luminescent material, and non-radiationtransition caused by the interaction can be avoided.

The organic EL device of the present invention is a device in which anorganic compound layer comprising a single layer or plural layers isformed between an anode and a cathode. In the case of the single layertype, a luminescent layer is provided between an anode and a cathode.The luminescent layer contains the luminescent material, and in additionthereto, it may contain a hole injecting material or an electroninjecting material in order to transport a hole injected from the anodeor an electron injected from the cathode to the luminescent material.The luminescent material has a very high fluorescent quantum efficiencyand a high hole transporting ability and electron transporting abilityin combination, and an even thin film is preferably formed. The organicEL element of the multilayer type includes (anode/hole injecting layer(hole transporting layer)/luminescent layer/cathode), (anode/luminescentlayer/electron injecting layer/cathode) and (anode/hole injecting layer(hole transporting layer)/luminescent layer/electron injectinglayer/cathode).

In the present invention, the luminescent layer described abovepreferably contains the arylamine compound of the present invention.Further, the organic compound layer described above preferably has ahole transporting layer, and the above hole transporting layerpreferably contains the arylamine compound of the present invention.

A preferred use method of the arylamine compound of the presentinvention includes adding it to any layer of the luminescent layer, theelectron injecting layer and the hole transporting layer in aconcentration of 0.5 to 100% by weight, more preferably 50 to 100% byweight. The organic EL element can be prevented from a reduction in aluminance and a life due to quenching by assuming a multilayerstructure. The luminescent material, other doping materials, a holeinjecting material and an electron injecting material can be used, ifnecessary, in combination. The other doping materials make it possibleto obtain a rise in the light emitting luminance and the luminousefficiency and luminance of a red color and a white color. The holeinjecting layer, the luminescent layer and the electron injecting layereach may be formed in a layer structure of two or more layers. In suchcase, as long as the hole injecting layer is concerned, a layer intowhich a hole is injected from an electrode is called a hole injectinglayer, and a layer which receives a hole from the hole injecting layerand transports it to a luminescent layer is called a hole transportinglayer. Similarly, as long as the electron injecting layer is concerned,a layer into which an electron is injected from an electrode is calledan electron injecting layer, and a layer which receives an electron fromthe electron injecting layer and transports it to the luminescent layeris called an electron transporting layer. The above respective layersare selected and used according to respective factors such as an energylevel of the materials, a heat resistance and an adhesion to the organiccompound layer or the metal electrode.

The organic EL device of the present invention preferably contains thearylamine compound of the present invention and the luminescent materialin at least one layer of the organic compound layers described above.

The luminescent material which can be used in the organic compound layertogether with the arylamine compound of the present invention includescondensed polycyclic aromatic compounds, and they include, for example,anthracene, naphthalene, phenanthrene, pyrene, tetracene, pentacene,coronene, chrysene, fluorescein, perylene, rubrene and derivativesthereof. Further, they include phthaloperylene, naphthaloperylene,perynone, phthaloperynone, naphthaloperynone, diphenylbutadiene,tetraphenylbutadiene, coumarin, oxadiazole, aldazine, bisbenzoxazoline,bisstyryl, pyrazine, cyclopentadiene, quinoline metal complexes,aminoquinoline metal complexes, benzoquinoline metal complexes, imine,diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran,polymethine, merocyanine, imidazole chelated oxynoid compounds,quinacridone, rubrene, stilbene base derivatives and fluorescentcoloring matters. However, it shall no be restricted to them.

Further, in the organic EL device of the present invention, the organiccompound layer described above is preferably prepared by laminating ahole transporting layer containing the arylamine derivative of thepresent invention and a luminescent layer comprising aphosphorescence-emitting metal complex and a host material.

The phosphorescence-emitting metal complex includes:

but shall not be restricted to them.

The host material described above includes condensed polycyclic aromaticcompounds, and they include, for example, anthracene, naphthalene,phenanthrene, pyrene, tetracene, pentacene, coronene, chrysene,fluorescein, perylene, rubrene and derivatives thereof. Further, theyinclude phthaloperylene, naphthaloperylene, perynone, phthaloperynone,naphthaloperynone, diphenylbutadiene, tetraphenylbutadiene, coumarin,oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine,cyclopentadiene, quinoline metal complexes, aminoquinoline metalcomplexes, benzoquinoline metal complexes, imine, diphenylethylene,vinylanthracene, diaminocarbazole, pyran, thiopyran, polymethine,merocyanine, imidazole chelated oxynoid compounds, quinacridone,rubrene, stilbene base derivatives and fluorescent coloring matters.However, it shall not be restricted to them.

Further, publicly known luminescent materials, doping materials, holeinjection materials and electron injection materials in addition to thearylamine compound of the present invention can be used, if necessary,in the luminescent layer described above.

The luminescent materials described above include those described above.

Capable of being used as the doping materials described above arepublicly known fluorescent coloring matters such as perylenederivatives, rubrene derivatives, coumarin derivatives,dicyanomethylenepyran derivatives, stilbene derivatives,tristyrylarylene derivatives and distyrylarylene derivatives. Amongthem, the distyrylarylene derivatives can be given as the preferredfluorescent coloring matters. Further preferably, styrylamine compoundssuch as arylamino-substituted distyrylarylene derivatives can be given.Also, arylamine compounds can preferably be used as well for the dopant.

Preferred as the hole injecting materials described above are compoundswhich are provided with ability to transport holes and have an effect ofinjecting holes from an anode and an excellent effect of injecting holesinto a luminescent layer or a luminescent material and which preventexcitons formed in the luminescent layer from transferring to anelectron injecting layer or an electron injecting material and areexcellent in a thin film-forming ability. To be specific, they includephthalocyanine derivatives, naphthalocyanine derivatives, porphyrinderivatives, oxazole, oxadiazole, triazole, imidazole, imidazolone,imidazolethione, pyrazoline, pyrazolone, tetrahydroimidazole, oxazole,oxadiazole, hydrazone, acylhydrazone, polyarylalkane, stilbene,butadiene, benzidine type triphenylamine, styrylamine typetriphenylamine, diamine type triphenylamine and derivatives thereof andhigh molecular materials such as polyvinylcarbazole, polysilane andconductive polymers, but they shall not be restricted thereto.

Among the above hole injecting materials, more effective hole injectionmaterials are aromatic tertiary amine derivatives or phthalocyaninederivatives. The specific examples of the aromatic tertiary aminederivatives are triphenylamine, tritolylamine, tolyldiphenylamine,N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine,N,N,N′,N′-(4-methylphenyl)-1,1′-phenyl-4,4′-diamine,N,N,N′,N′-(4-methylphenyl)-1,1′-biphenyl-4,4′-diamine,N,N′-diphenyl-N,N′-dinaphthyl-1,1′-biphenyl-4,4′-diamine,N,N′-(methylphenyl)-N,N′-(4-n-butylphenyl)-phenanthrene-9,10-diamine,N,N-bis(4-di-4-triaminophenyl)-4-phenyl-cyclohexane and oligomers orpolymers having aromatic tertiary amine skeletons thereof, but theyshall not be restricted thereto. The specific examples of thephthalocyanine (Pc) derivatives include phthalocyanine derivatives suchas H₂Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc,ClInPc, ClSnPc, Cl₂SnPc, (HO)AlPc, (HO)GaPc, VoPc, TiOPc, MoOPc andGaPc-O-GaPc and naphthalocyanine derivatives, but they shall not berestricted thereto.

Preferred as the electron injecting materials described above arecompounds which are provided with ability to transport electrons andhave an effect of injecting electrons from a cathode and an excellenteffect of injecting electrons into a luminescent layer or a luminescentmaterial and which prevent excitons formed in the luminescent layer fromtransferring to a hole injecting layer and are excellent in a thinfilm-forming ability. To be specific, they include fluorenone,anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole,oxadiazole, triazole, imidazole, perylenetetracarboxylic acid,fluorenilidenemethane, anthraquinodimethane, anthrone and derivativesthereof, but they shall not be restricted thereto. Further, the chargeinjecting property can be raised by adding an electron receivingsubstance to the hole injecting material and adding an electron donatingsubstance to the electron injecting material.

Among the above hole injecting materials, more effective electroninjecting materials are metal complex compounds or nitrogen-containingfive-membered derivatives. The specific examples of the metal complexcompounds include 8-hydroxyquinolinate lithium,bis(8-hydroxyquinolinate) zinc, bis(8-hydroxyquinolinate) copper,bis(8-hydroxyquinolinate) manganese, tris(8-hydroxyquinolinate)aluminum, tris(2-methyl-8-hydroxyquinolinate) aluminum,tris(8-hydroxyquinolinate) gallium, bis(10-hydroxybenzo[h]quinolinate)beryllium, bis(10-hydroxybenzo[h]quinolinate) zinc,bis(2-methyl-8-quinolinate) chlorogallium, bis(2-methyl-8-quinolinate)(o-crezolate) gallium, bis(2-methyl-8-quinolinate) (o-naphtholate)aluminum, bis(2-methyl-8-quinolinate) (1-naphtholate) aluminum andbis(2-methyl-8-quinolinate) (2-naphtholate) gallium, but they shall notbe restricted thereto.

The nitrogen-containing five-membered derivatives are preferablyoxazole, thiazole, oxadiazole, thiadiazole and triazole derivatives. Tobe specific, they include 2,5-bis(1-phenyl)-1,3,4-oxazole, dimethylPOPOP, 2,5-bis(1-phenyl)-1,3,4-thiazole,2,5-bis(1-phenyl)-1,3,4-oxadiazole,2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-oxadiazole,2,5-bis(1-naphthyl)-1,3,4-oxadiazole,1,4-bis[2-(5-phenyloxadiazolyl)]benzene,1,4-bis[2-(5-phenyloxadiazolyl)-4-tert-butylbenzene],2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-thiadiazole,2,5-bis(1-naphthyl)-1,3,4-thiadiazole,1,4-bis[2-(5-phenylthiadiazolyl)]benzene,2-(4′-tert-butylphenyl)-5-(4″-biphenyl)-1,3,4-triazole,2,5-bis(1-naphthyl)-1,3,4-triazole and1,4-bis[2-(5-phenyltriazolyl)]benzene, but they shall not be restrictedthereto.

In the present invention, an inorganic compound layer may be providedbetween the luminescent layer and the electrode in order to improve thecharge injecting property. Such inorganic compound includes alkalinemetal compounds (fluorides, oxides and the like) and alkaline earthmetal compounds, and to be specific, it includes LiF, Li₂O, RaO, SrO,BaF₂ and SrF₂.

The conductive material used for the anode in the organic EL device ofthe present invention is suitably a material having a work function oflarger than 4 eV, and used therefor are carbon, aluminum, vanadium,iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium andalloys thereof, metal oxides such as tin oxide and indium oxide whichare used for an ITO substrate and an NESA substrate and organicconductive resins such as polythiophene and polypyrrole.

The conductive material used for the cathode in the organic EL device ofthe present invention is suitably a material having a work function ofsmaller than 4 eV, and used therefor are magnesium, calcium, tin, lead,titanium, yttrium, lithium, ruthenium, manganese, aluminum and alloysthereof, but it shall not be restricted to them. The representativeexamples of the alloys include, for example, magnesium/silver,magnesium/indium and lithium/aluminum. A proportion of the alloys iscontrolled according to a temperature of the vapor deposition source,the atmosphere and the vacuum degree, and the suitable proportion isselected. The anode and the cathode may be formed, if necessary, in alayer structure of two or more layers.

In the organic EL device of the present invention, it is preferred thatat least one surface thereof is sufficiently transparent in aluminescent wavelength area of the device in order to efficiently emitlight. Further, the substrate is preferably transparent as well. Atransparent electrode is set up by a method such as vapor deposition andsputtering using the conductive materials described above so thatprescribed transparency is secured. The electrode on the luminescentface is preferably controlled to a light transmittance of 10% or more.The substrate shall not be restricted as long as it has mechanical andthermal strengths and is transparent, and it includes a glass substrateand a transparent resin film. The transparent resin film includespolyethylene, an ethylene-vinyl acetate copolymer, an ethylene-vinylalcohol copolymer, polypropylene, polystyrene, polymethyl methacrylate,polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, nylon,polyether ether ketone, polysulfone, polyether sulfone, atetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyvinylfluoride, a tetrafluoroethylene-ethylene copolymer, atetrafluoroethylene-hexafluoropropylene copolymer,polychlorotrifluoroethylene, polyvinylidene fluoride, polyester,polycarbonate, polyurethane, polyimide, polyetherimide, polyimide andpolypropylene.

In the organic EL device of the present invention, in order to improvestability against the temperature, the humidity and the environment, aprotective layer can be provided on the surface of the device, and thewhole part of the device can be protected by a silicon oil, a resin andthe like. The respective layers of the organic EL device can be formedby applying any of a dry film forming method such as vacuum vapordeposition, sputtering, plasma and ion plating and a wet film formingmethod such as spin coating, dipping and flow coating. The filmthickness shall not specifically be restricted, and it has to be set toa suited film thickness. If the film thickness is too large, largevoltage has to be applied in order to obtain a constant light output, sothat the efficiency is deteriorated. If the film thickness is too small,pinholes are formed, and the satisfactory light emitting luminance isnot obtained when applying an electric field. Usually, the filmthickness falls in a range of suitably 5 nm to 10 μm, preferably 10 nmto 0.2 μm.

In the case of the wet film forming method, materials for forming therespective layers are dissolved or dispersed in a suitable solvent suchas ethanol, chloroform, tetrahydrofuran and dioxane to form thin films,and the solvent may be any one. Suitable resins and additives may beused in any organic thin film in order to improve the film formingproperty and prevent pinholes from being formed on the film. The resinswhich can be used include insulating resins such as polystyrene,polycarbonate, polyallylate, polyester, polyamide, polyurethane,polysulfone, polymethyl methacrylate, polymethyl acrylate and celluloseand copolymers thereof, photoconductive resins such aspoly-N-vinylcarbazole and polysilane and conductive resins such aspolythiophene and polypyrrole. The additives include antioxidants, UVabsorbers and plasticizers.

The organic EL device of the present invention can be used, for example,as a plane luminant for flat panel displays of wall-mounted televisionsets, a backlight for copying machines, printers and liquid crystaldisplays, a light source for meters, a display board and a marker lamp.

EXAMPLES

Next, the present invention shall be explained in further details withreference to examples, but the present invention shall by no means berestricted by these examples.

Synthetic Example 1 Synthesis of Intermediate A

A three neck flask of 1000 ml was charged with 2-bromofluorene 100 g(manufactured by Tokyo Kasei Kogyo Co., Ltd.), dimethylsulfoxide (DMSO)200 ml, benzyltriethylammonium chloride 1.9 g (manufactured by Wako PureChemical Industries Ltd.) and a sodium hydroxide aqueous solution of 50%by weight 130 g under argon atmosphere.

This reactor was put in a water bath, and 1,5-dibromopentane 88.1 g(manufactured by Wako Pure Chemical Industries Ltd.) was added theretowhile stirring.

After reacted for 5 hours, 2000 ml of water was added, and the solutionwas extracted with 1000 ml of toluene. The organic layer was dried onmagnesium sulfate, and the solvent was distilled off by means of arotary evaporator to obtain 111 g of an oil which was the intendedcompound (yield: 91%).

Synthetic Example 2 Synthesis of Intermediate B

Reaction was carried out in the same manner as in Synthetic Example 1,except that 1,6-dibromohexane 93.5 g (manufactured by Wako Pure ChemicalIndustries Ltd.) was used in place of 1,5-dibromopentane to obtain 97 gof an oil which was the intended compound (yield: 76%)

Example 1 Synthesis of Compound (HT-01)

The intermediate (B) 1.2 g, N,N′-di(naphthyl-2-yl)-1,4-phenylenediamine0.60 g (manufactured by Kanto Chemical Co., Inc.), sodium t-butoxide 1.2g (manufactured by Hiroshima Wako Corporation),bis(triphenylphosphine)palladium (II) chloride 0.3 g (manufactured byTokyo Kasei Kogyo Co., Ltd.) and xylene 300 ml were put under argon flowto react them at 130° C. for 24 hours.

After cooled down, 500 ml of water was added thereto, and the mixturewas filtered through celite. The filtrate was extracted with toluene,and the extract was dried on anhydrous magnesium sulfate. This wasconcentrated under reduced pressure, and the resulting crude product wasrefined by means of a column and recrystallized from toluene. It wasfiltered and then dried to obtain 0.74 g of a pale yellow powder.

The powder thus obtained was identified as the compound (HT-01) (yield:54%) by FD-MS (field desorption mass spectrum) analysis since a mainpeak of m/z=825 corresponding to C₆₂H₅₂N₂=824 was obtained. The glasstransition temperature was 118° C.

Example 2 Synthesis of Compound (HT-02)

The intermediate (A) 1.2 g, N,N′-di(naphthyl-2-yl)-1,4-phenylenediamine0.60 g (manufactured by Kanto Chemical Co., Inc.), sodium t-butoxide 1.2g (manufactured by Hiroshima Wako Corporation),bis(triphenylphosphine)palladium (II) chloride 0.3 g (manufactured byTokyo Kasei Kogyo Co., Ltd.) and xylene 300 ml were put under argon flowto react them at 130° C. for 24 hours.

After cooled down, 500 ml of water was added thereto, and the mixturewas filtered through celite. The filtrate was extracted with toluene,and the extract was dried on anhydrous magnesium sulfate. This wasconcentrated under reduced pressure, and the resulting crude product wasrefined by means of a column and recrystallized from toluene. It wasfiltered and dried to obtain 0.87 g of a pale yellow powder.

The powder thus obtained was identified as the compound (HT-02) (yield:66%) by FD-MS analysis since a main peak of m/z=797 corresponding toC₆₀H₄₈N₂=796 was obtained. The glass transition temperature was 117° C.

Example 3 Synthesis of Compound (HT-03)

The intermediate (B) 1.3 g, N,N-diphenyl-4,4′-benzidine 0.56 g(manufactured by Wako Pure Chemical Industries Inc.), sodium t-butoxide1.2 g (manufactured by Hiroshima Wako Corporation),bis(triphenylphosphine)palladium (II) chloride 0.3 g (manufactured byTokyo Kasei Kogyo Co., Ltd.) and xylene 300 ml were put under argon flowto react them at 130° C. for 24 hours.

After cooled down, 500 ml of water was added thereto, and the mixturewas filtered through celite. The filtrate was extracted with toluene,and the extract was dried on anhydrous magnesium sulfate. This wasconcentrated under reduced pressure, and the resulting crude product wasrefined by means of a column and recrystallized from toluene. It wasfiltered and then dried to obtain 0.96 g of a pale yellow powder.

The powder thus obtained was identified as the compound (HT-03) (yield:72%) by FD-MS analysis since a main peak of m/z=801 corresponding toC₆₀H₅₂N₂=800 was obtained. The glass transition temperature was 124° C.

Example 4 Synthesis of Compound (HT-04)

The intermediate (A) 1.2 g, N,N-diphenyl-4,4′-benzidine 0.56 g(manufactured by Wako Pure Chemical Industries Inc.), sodium t-butoxide1.2 g (manufactured by Hiroshima Wako Corporation),bis(triphenylphosphine)palladium (II) chloride 0.3 g (manufactured byTokyo Kasei Kogyo Co., Ltd.) and xylene 300 ml were put under argon flowto react them at 130° C. for 24 hours.

After cooled down, 500 ml of water was added thereto, and the mixturewas filtered through celite. The filtrate was extracted with toluene,and the extract was dried on anhydrous magnesium sulfate. This wasconcentrated under reduced pressure, and the resulting crude product wasrefined by means of a column and recrystallized from toluene. It wasfiltered and then dried to obtain 0.94 g of a pale yellow powder.

The powder thus obtained was identified as the compound (HT-04) (yield:73%) by FD-MS analysis since a main peak of m/z=772 corresponding toC₅₈H₄₈N₂=772 was obtained. The glass transition temperature was 124° C.

Example 5 Synthesis of Compound (HT-05)

The intermediate (B) 2.6 g, 4,4″-diamino-p-terphenylene 0.43 g(manufactured by Lancaster Co., Ltd.), sodium t-butoxide 2.0 g(manufactured by Hiroshima Wako Corporation),bis(triphenylphosphine)palladium (II) chloride 0.6 g (manufactured byTokyo Kasei Kogyo Co., Ltd.) and xylene 300 ml were put under argon flowto react them at 130° C. for 24 hours.

After cooled down, 500 ml of water was added thereto, and the mixturewas filtered through celite. The filtrate was extracted with toluene,and the extract was dried on anhydrous magnesium sulfate. This wasconcentrated under reduced pressure, and the resulting crude product wasrefined by means of a column and recrystallized from toluene. It wasfiltered and then dried to obtain 0.71 g of a pale yellow powder.

The powder thus obtained was identified as the compound (HT-05) (yield:36%) by FD-MS analysis since a main peak of m/z=1189 corresponding toC₉₀H₈₀N₂=1188 was obtained. The glass transition temperature was 131° C.

Example 6 Synthesis of Compound (HT-06)

The intermediate (A) 2.4 g, 4,4″-diamino-p-terphenylene 0.43 g(manufactured by Lancaster Co., Ltd.), sodium t-butoxide 2.0 g(manufactured by Hiroshima Wako Corporation),bis(triphenylphosphine)palladium (II) chloride 0.6 g (manufactured byTokyo Kasei Kogyo Co., Ltd.) and xylene 300 ml were put under argon flowto react them at 130° C. for 24 hours.

After cooled down, 500 ml of water was added thereto, and the mixturewas filtered through celite. The filtrate was extracted with toluene,and the extract was dried on anhydrous magnesium sulfate. This wasconcentrated under reduced pressure, and the resulting crude product wasrefined by means of a column and recrystallized from toluene. It wasfiltered and then dried to obtain 0.77 g of a pale yellow powder.

The powder thus obtained was identified as the compound (HT-06) (yield:41%) by FD-MS analysis since a main peak of m/z=1133 corresponding toC₈₆H₇₂N₂=1132 was obtained. The glass transition temperature was 132° C.

Synthetic Example 3 Synthesis of N,N-di-(4-biphenylyl)benzamide

A three neck flask of 100 ml was charged with 4-bromobiphenyl 10.0 g(manufactured by Tokyo Kasei Kogyo Co., Ltd.), benzamide 2.31 g(manufactured by Tokyo Kasei Kogyo Co., Ltd.), cuprous iodide 0.36 g(manufactured by Kanto Chemical Co., Inc.) and anhydrous potassiumcarbonate 5.8 g (manufactured by Kanto Chemical Co., Inc.). Further, astirring rod was put therein, and rubber caps were set at both end necksof the flask. Set were a coiled tube for refluxing at the central neck,a three-way cock thereon and a balloon filled with argon gas, and thesystem was substituted three times with argon gas filled in the balloonby means of a vacuum pump.

Next, 50 ml of diethylbenzene was added thereto through a rubber septumby means of a syringe, and the flask was set on an oil bath. Thetemperature was gradually elevated up to 200° C. while stirring thesolution. After 6 hours, the flask was removed from the oil bath toterminate the reaction, and it was left standing for 12 hours underargon atmosphere.

The reaction solution was transferred into a separating funnel, and 100ml of dichloromethane was added thereto to dissolve the precipitate. Thesolution was washed with 60 ml of saturated brine, and then the organiclayer was dried on anhydrous potassium carbonate. The solvent wasdistilled off from an organic layer obtained by filtering off potassiumcarbonate, and 200 ml of toluene and 40 ml of ethanol were added to theresulting residue. A drying tube was fitted thereto, and the solutionwas heated to 80° C. to completely dissolve the residue. Then, it wasleft standing for 12 hours and gradually cooled down to room temperatureto thereby carry out recrystallization.

Crystal deposited was filtered and dried under vacuum at 60° C. toobtain 7.22 g of N,N-di-(4-biphenylyl)benzamide.

Synthetic Example 4 Synthesis of Intermediate C

A three neck flask of 1000 ml was charged with 2-bromofluorene 100 g(manufactured by Tokyo Kasei Kogyo Co., Ltd.), DMSO 200 ml,benzyltriethylammonium chloride 1.9 g (manufactured by Wako PureChemical Industries Ltd.) and a sodium hydroxide aqueous solution of 50%by weight 130 g under argon atmosphere.

This reactor was put in a water bath, and 1,2-dibenzyl bromide 108 g(manufactured by Wako Pure Chemical Industries Ltd.) was added theretowhile stirring.

After reacted for 5 hours, 2000 ml f water was added thereto, and thesolution was extracted with 1000 ml of toluene. The organic layer wasdried on magnesium sulfate, and the solvent was distilled off by meansof a rotary evaporator to obtain 105 g of an oil which was the intendedcompound (yield: 74%).

Example 7 Synthesis of Compound (HT-07)

A two neck flask of 50 ml was charged withN,N-di-(4-biphenylyl)benzamide 1.00 g, the intermediate (C) 1.00 g,cuprous iodide 0.021 g and potassium hydroxide 0.51 g, and a rubber capwas mounted on one neck of the flask. Set were a coiled tube forrefluxing at the central neck, a three-way cock thereon and a balloonfilled with argon gas, and the system was substituted three times withargon gas filled in the balloon by means of a vacuum pump.

Next, 20 ml of xylene was added thereto through a rubber septum by meansof a syringe, and the flask was set on an oil bath. The temperature wasgradually elevated up to 140° C. while stirring the solution. Afterstirring at 140° C. for 6 hours, the flask was removed from the oil bathand left standing for 12 hours at room temperature.

A precipitate deposited was completely dissolved in 50 ml ofdichloromethane, and the solution was transferred into a separatingfunnel. The solution was washed with 50 ml of saturated brine, and thenthe organic layer separated was dried on anhydrous potassium carbonate.After filtering, the solvent was distilled off, and 150 ml of tolueneand 50 ml of ethanol were added to the resulting residue. A drying tubewas mounted thereon, and the solution was heated up to 80° C. todissolve the precipitate. Then, it was gradually cooled down to roomtemperature. Next, the precipitate was filtered and washed with a smallamount of toluene and ethanol, and then it was dried at 60° C. for 3hours by means of a vacuum dryer to obtain 0.72 g of a yellow powder.

The powder thus obtained was identified as the compound (HT-07) (yield:52%) by FD-MS analysis since a main peak of m/z=587 corresponding toC₄₅H₃₃N=587 was obtained. The glass transition temperature was 116° C.

Example 8 Production and Evaluation of Organic EL Device

A glass substrate (manufactured by Geomatec Co., Ltd.) of 25 mm×75mm×1.1 mm thickness equipped with an ITO transparent electrode wassubjected to supersonic wave washing in isopropyl alcohol for 5 minutesand then to UV ozone washing for 30 minutes.

The glass substrate equipped with an ITO transparent electrode lineafter washing was mounted on a substrate holder of a vacuum depositingapparatus, and a film of the following compound H232 having a filmthickness of 60 nm was formed on a face at a side on which thetransparent electrode line was formed so that the transparent electrodedescribed above was covered. This H232 film functions as a holeinjecting layer. Next, a film of the compound (HT-01) having a filmthickness of 20 nm described above was formed on the H232 film. Thisfilm functions as a hole transporting layer.

Further, the following compound EM1 was deposited as a host material toform a film having a film thickness of 40 nm. The following aminecompound D1 having a styryl group was deposited as a luminescent dopantat the same time as above so that a weight ratio of EM1 to D1 was 40:2.This film functions as a luminescent layer.

A film of the following compound Alq having a film thickness of 20 nmwas formed on the above film. This film functions as an electroninjecting layer. Further, an LiF film (film thickness: 1 nm) was formedas an electron injecting layer (or a cathode). Metal Al was deposited onthis LiF film to form a metal cathode, whereby an organic EL device wasproduced.

This device was subjected to a current-carrying test to obtain blueluminescence having a light emitting luminance of 153 nit, a maximumlight emitting luminance of 50,000 nit and a luminous efficiency of 4.8cd/A at a direct current voltage of 6 V. Further, it was stored in anatmosphere of 105° C. for 500 hours to carry out a heat resistancestorage test. A direct current voltage of 6 V was applied as was thecase with before the test to find that a luminance of 98% (luminancepreserving rate: 98%) based on the initial luminance was shown.

Examples 9 to 13 Production and Evaluation of Organic EL Devices

Organic EL devices were produced in the same manner as in Example 8,except that in Example 8, compounds shown in Table 1 were used in placeof the compound (HT-01), and the current-carrying test and the heatresistance storage test were carried out in the same manner as inExample 8. The results thereof are shown in Table 1.

Comparative Example 1 Production and Evaluation of Organic EL Device

An organic EL device was produced in the same manner as in Example 8,except that in Example 8, the following compound TPAF (glass transitiontemperature: lower than 100° C.) was used in place of the compound(HT-01), and the current-carrying test and the heat resistance storagetest were carried out in the same manner as in Example 8. The resultsthereof are shown in Table 1.

Comparative Example 2 Production and Evaluation of Organic EL Device

An organic EL device was produced in the same manner as in Example 8,except that in Example 8,N,N′-di(4-biphenyl)-N,N′-[2-(9,9-dimethylfluorenyl)]-4,4′-diaminobiphenyl(DFDBBZ shown below) (glass transition temperature: lower than 100° C.)was used in place of the compound (HT-01), and the current-carrying testand the heat resistance storage test were carried out in the same manneras in Example 8. The results thereof are shown in Table 1.

TABLE 1 Light emitting Luminance preserving Hole luminance Luminous rateafter stored at transporting (voltage 6 V) efficiency Luminescent 105°C. for 500 hours material (nit) (cd/A) color (%) Example 8 HT-01 153 4.8Blue 98 Example 9 HT-02 147 4.7 Blue 99 Example 10 HT-03 158 5.1 Blue 99Example 11 HT-04 159 5.1 Blue 98 Example 12 HT-05 162 5.2 Blue 98Example 13 HT-06 161 4.7 Blue 98 Comparative TPAF 138 4.4 Blue 10Example 1 Comparative DFDBBZ 128 2.2 Yellow 82 Example 2

As shown in Table 1, TPAF used in Comparative Example 1 is poor in aheat resistance because of a low glass transition temperature, and theluminance after stored at 105° C. for 500 hours is lowered down to 10%of the luminance before storing.

DFDBBZ used in Comparative Example 2 has a high glass transitiontemperature and is satisfactory in a heat resistance. However, it has ahigh flatness in an end part having a fluorene skeleton and thereforebrings about exciplex with the luminescent material. Accordingly, it isconsidered that the luminescent color is shifted to a longer wavelengthand reduced in efficiency.

On the other hand, the organic EL devices produced in Examples 8 to 13using the arylamine compounds according to the present invention areimproved in a light emitting luminance and a luminous efficiency andexcellent in a heat resistance. This is considered to be attributable tothe facts that the arylamine compounds according to the presentinvention have a high glass transition temperature of 100° C. or higherdue to a fluorene skeleton having a specific structure and that thecyclic structure introduced into the end makes it less liable to bringabout exciplex with the luminescent layer.

Example 14 Production and Evaluation of Organic EL Device

An organic EL device was produced in the same manner as in Example 8,except that in Example 8, Alq and rubrene were deposited in a weightratio of 30:1 in place of the compounds EM1 and D1 to form a film havinga film thickness of 40 nm.

This device was subjected to a current-carrying test to obtain blueluminescence having a light emitting luminance of 1,300 nit, a maximumlight emitting luminance of 98,000 nit and a very high luminousefficiency of 9.5 cd/A at a direct current voltage of 6 V. Further, itwas stored in an atmosphere of 105° C. for 500 hours to carry out a heatresistance storage test. A direct current voltage of 6 V was applied aswas the case with before the test to find that a luminance of 99%(luminance preserving rate: 99%) based on the initial luminance wasshown.

Further, the device was operated in an initial luminance of 1,000 nit ata constant current to carry out a life test to find that the half lifewas as very long as 6,900 hours. It can be found from the above mattersthat the arylamine compound of the present invention is very excellentas a hole transporting compound

Comparative Example 3 Production and Evaluation of Organic EL Device

An organic EL device was produced in the same manner as in Example 14,except that in Example 14, DFDBBZ was used in place of the compound(HT-01). This device was operated in an initial luminance of 1,000 nitat a constant current to carry out a life test to find that the halflife was as short as 1,850 hours.

Example 15 Production and Evaluation of Organic EL Device

An organic EL device. was produced in the same manner as in Example 11,except that in Example 11, only Alq was deposited in place of thecompounds EM1 and D1 used for the luminescent layer to form a filmhaving a film thickness of 40 nm. A luminescent dopant was not used.

The device thus obtained was subjected to the current-carrying test andthe heat resistance storage test in the same manner as in Example 8, andthe results thereof are shown in Table 2.

Comparative Example 4 Production and Evaluation of Organic EL Device

An organic EL device was produced in the same manner as in Example 15,except that in Example 15, the compound DFDBBZ was used in place of thecompound HT-04. A luminescent dopant was not used.

The device thus obtained was subjected to the current-carrying test andthe heat resistance storage test in the same manner as in Example 8, andthe results thereof are shown in Table 2. TABLE 2 Light emittingLuminance preserving Hole luminance Luminous rate after stored attransporting (voltage 6 V) efficiency Luminescent 105° C. for 500 hoursmaterial (nit) (cd/A) color (%) Example 15 HT-04 115 3.6 Yellowish 110green Comparative DFDBBZ 121 2.4 Yellowish 87 Example 4 green

As shown in Table 2, the device using the compound DFDBBZ used inComparative Example 4 has a low initial luminous efficiency as comparedwith that of the device produced in Example 15 using HT-04. Further, thepreserving rate after stored at high temperature is 90% or lower. It isconsidered that DFDBBZ provides the device with a low efficiency and alow luminance preserving rate due to any interaction.

Example 17

An organic EL device was produced in the same manner as in Example 8,except that in Example 8, used were the following compound CBP in placeof the compound EM1 used for the luminescent layer and the compoundIr(ppy)₃ described above in place of the compound D1 and that thefollowing compound BAlq for forming a film having a film thickness of 10nm and then the compound Alq for forming a film having a film thicknessof 20 nm were deposited in place of depositing the compound Alq in theelectron injecting layer to form a film having a film thickness of 20nm.

The device thus obtained was measured for a luminous efficiency at adirect current voltage of 6 V to find that it was 34 cd/A.

Comparative Example 5 Production and Evaluation of Organic EL Device

An organic EL device was produced in the same manner as in Example 17,except that in Example 17, the following compound NPD was used in placeof the compound HT-01. A luminescent dopant was not used.

The device thus obtained was measured for a luminous efficiency at adirect current voltage of 6 V to find that it was 26 cd/A.

Industrial Applicability

The organic EL device using the novel arylamine compound of the presentinvention has a high luminance, a high heat resistance and a long life,and it is excellent in a hole transporting property and has a highluminous efficiency. Accordingly, the organic EL device of the presentinvention is useful as a plane luminant for wall-mounted television setsand a backlight for displays.

1. An arylamine compound represented by the following Formula (1):

wherein X is a substituted or non-substituted aromatic hydrocarbon grouphaving 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; Ar¹, Ar², Ar³ and Ar⁴each are independently a substituted or non-substituted group 6 to 40carbon atoms or a substituted or non-substituted heterocyclic grouphaving 5 to 40 carbon atoms; provided that at least one of Ar¹, Ar², Ar³and Ar⁴ is a group represented by the following Formula (2); Ar¹, Ar²,Ar³ and Ar⁴ may be the same as or different from each other, and theymay be combined with adjacent ones to form a saturated or unsaturatedring; and p is an integer of 0 to 2:

wherein R¹ and R² each are independently a hydrogen atom, a substitutedor non-substituted amino group, a substituted or non-substituted alkylgroup having 1 to 50 carbon atoms, a substituted or non-substituted arylgroup having 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; R³ represents an atomicgroup which forms a cyclic structure; Ar⁵ is a single bond or a divalentgroup comprising a substituted or non-substituted aromatic hydrocarbongroup having 6 to 40 carbon atoms or a substituted or non-substitutedheterocyclic group having 5 to 40 carbon atoms; L is a single bond, —O—,—S—, —NR⁴— or —CR⁵R⁶— (R⁴, R⁵ and R⁶ each are independently asubstituted or non-substituted alkyl group having 1 to 50 carbon atomsor a substituted or non-substituted aryl group having 6 to 40 carbonatoms); s, q and r each are an integer of 0 to 2; and R¹ and R² may becombined with each other to form a ring.
 2. The aryl amine compound asdescribed in claim 1, wherein in Formula (1) described above, thearomatic hydrocarbon group represented by X is a monovalent, divalent ortrivalent residue of benzene, biphenyl, terphenyl, naphthalene,fluorene, pyrene, spirobifluorene or stilbene.
 3. The aryl aminecompound as described in claim 1, wherein in Formula (1) describedabove, the aromatic hydrocarbon group represented by X is a monovalent,divalent or trivalent residue of carbazole, dibenzofurane,dibenzothiophene, fluorenone, oxazole, oxadiazole, thiadiazole orbenzimidazole.
 4. The aryl amine compound as described in claim 1,wherein in Formula (1) described above, the aryl group represented byAr¹ to Ar⁴ each are independently phenyl or a polycyclic aromatic group.5. The aryl amine compound as described in claim 1, being a material foran organic electroluminescent device.
 6. The aryl amine compound asdescribed in claim 1, being a hole transporting material for an organicelectroluminescent device.
 7. An organic electroluminescent device inwhich an organic compound layer comprising one layer or plural layersincluding at least a luminescent layer is interposed between a cathodeand an anode, wherein at least one of the above organic compound layerscontains the arylamine derivative as described in claim
 1. 8. Theorganic electroluminescent device as described in claim 7, wherein theluminescent layer described above contains the arylamine derivative asdescribed in claim
 1. 9. The organic electroluminescent device asdescribed in claim 7, wherein the luminescent layer described above hasa hole transporting layer, and the above hole transporting layercontains the arylamine derivative.
 10. An organic electroluminescentdevice in which an organic compound layer comprising one layer or plurallayers including at least a luminescent layer is interposed between acathode and an anode, wherein at least one of the above organic compoundlayers contains the arylamine derivative as described in claim 1 and aluminescent material.
 11. An organic electroluminescent device in whichan organic compound layer comprising one layer or plural layersincluding at least a luminescent layer is interposed between a cathodeand an anode, wherein the above organic compound layer is prepared bylaminating a hole transporting layer containing the arylamine derivativeas described in claim 1 and a luminescent layer comprising aphosphorescence-emitting metal complex and a host material.